Substrates can be used for a variety of purposes, including starting layers in various fabrication processes. Frequently, these substrates can have microfabricated structures built upon or with them. For example, in microreactors, a flow path can be built within and/or upon a substrate, allowing for microscale manipulation of a sample by these microstructures. Traditionally, the final microstructures, such as a flow path, are formed using a combination of photolithography, etching, and/or other techniques.